Acknowledging device for train-control systems



Q April 22, 1930. c. A. CHRISTOFFERSON 1,755,772

ACKNOWLEDGING DEVICE FOR TRAIN CONTROL SYSTEMS Filed Jan. '30, 1926Patented Apr. '22, 1930 i I U JER-AL RAILWA ,smile co viren i CHRISTIANA. cHRIsroFrERsonIor' s'rl Pent, Minn-more, Assreivoaro THE-em,

i AcoRroRArroN or NEW YORK I a oKnow EDenvennvIcnrcR ruliimconrnorisYsrEMs V l Application mammary 30,1926; Serial 'No'. 84,980.

i vinvention i' relates to v automatic train control systems, and moreparticularly 7 to la device or mechanism, commonly termed an v -thetrain to a stopatle aclrcaution orstop signal, or "correspondmgcontrolpo nt, un-

acknowledging device, which is employed in certain types of traincontrol systems to 'en;

force vigilance on-the part of the engineer.

In the application of certain types of'auto- I I matic traincontrol'systems to railroads,itr

has been proposed to provide means which will automatically apply thebrakes and bring less the engineer takes suitable anticipatory action,ordinarily i termed acknowledgement. To carry out {theprinciples'fofacknowledgment itis desirable to include'in the sys'tem.

I v a manually operable acknowledging device,

wvhich the engineermanipulates to avoid the automatic brake application,and which "is wise suitably protected,'so that thee'ngineer I cannotfasten or h'old'thi's 'device in'its efiec ti ve position, "but mustacknowledgefeyery unfavorable 's'ig'nal indication. One type of a systemembodyingthis aclinowledgin'g'- feature is disclosed in thepatent toWVinthr-op .acknowledging"device. One-'pbjece of; the present inventionis t'o provide a simple,-.

eflicient," and "reliable time element mechan1s m,"compr-1s1n'g-]1n oneform an electric motor and rejdu'ction gearing," According to theiinvention," 'su'e'li an electric motor and 1: iOtheru-objects, purposesandw characteri'sreductionggearing "as" a time 'element; mechamsm 1Scombined with circu ts and" control- -lin gicontacts in s uchaway thattheengineer may {acknowledge for a limited I time only,

1 andso thatordinary failures, such as broken wires '1 andiconfnctions'fwill be' 1 "on the side of safety;- Inf particularflitis proposed tovprovide an org'anizatiqn in which the time element vmechanism "has tofunction in order to effect acknowledgement; and failures "of thismechanism ;W i1l': gprevent acknowledg t fe t ires 0f the inventi'oifiwilb iili'part effective ior a limited time only; or. otherment of theinvention, the parts and circuits being.illustrated-more with the viewof making it'easy to understand the:natureofthe illustrating theparticular construction ,fpret erably employedin practice. 2 a

drawing which shows in aasimplified andd agrammatic manner 1 onespecificj embodi-y;

invention, rather than with the purpose; of l Referring to the" drawing,since the acknowled'ging" feature, constituting the sub ject matter'ofthe present invention,- is ap-, plicable l, to various .type's ofitrain '"fcontrol' systems, botha speed control vand 1 a permiszsiv'estop system, and may beemployed with variousitypes and forms,ofmeans'fortrans- Y mitting impulses on the trackway to themovingtrain, either by intermittent "or contin- ;uous control, no attempt hasbeen'm'ade to illustrate any particular type vof f'trainf con jtrolsystem. :In these-various systems,:how ever,'there existsm some form orother-a suitable means-whichoperates ateach f'cautionor danger sign'akorcorresponding-cou- -trol' point, when acknowledgment should'be; j made."Ordinarily",- thismeaus takes thefornr of a normally closed contact,"automatically openedat the control points; :fand;to: illus trate theadaptability andv application of -;tl 1e invention, a contact 'Aisshown, assumed to "opened for a limited: interval of I time, dis tanceor: the like, atheach: control point! I Assuming such acontrollingcontact A,=or equivalent, the organization inv general,constituting theinvention, comprises a stick mbe controlled by'relay GR,and temporarily opened at each caution or st0p. signal.' It should beunderstood that this (l0ntaCt::Al.iS

layQSR abrakencontrol device,.assumed to'be 1 c an electro-pneumatievalvev EPV; a reset switch. RS an acknowledging;contactor or push buttonAC and a time element mechanism-, 'including an electric motor'M, aspeedresponsive device oricentrifu ge C and asso ciated contacts andcircuits. I. All of these parts are carried on'the railway vehiclea'ortrain. The relay SR is of any suitable, type, such We l 1mm :eqmmqnlyused -ea or having otherauxiliary features inaccordance wit1 1 theestablished practice of the art.

locomotives or other railwayvehicles. The

electro-pneumatic valve EPV isassumed to 7 act upon suitable brakeapplying means to give the desired automatic application of r thebrakes, either by venting the brake pipe direct, antomatic ally.operatingthe engineers brake' -valve, or the'like, producing a limitedreduction in brake-pipe pressure, if desired,

The reset switch BS is of any suitable construction for opjeningabreakin .a normally closed circuit, and closing a break in anormally opencircuit. I As shown, this reset switch RS comprises a simple springreturn plunger, having; a contact member 3 movable. from engagementwltha palr of stationary contacts, ind cated conventionally as arrows,

into engagement with another pair of contacts. This resetswitch isordinarily located so-thatit is accessible only from the ground,

'7 and cannot be -operated until the ti' ain has been brought :to astop. The acknowledging contactor AG, asshowmcomprises asiinplepushbutton or strap key 23, having normaflly closed, and normally opencontacts. v

The time element mechanism comprises a small electric motor, ordinarily.dji'rect' current, whi'ch has constant speed characterist cs. Thismotorlsshown diagrammatically as a shunt-wound motor; The motor "Mdrives the shaft l, which is connected by i Y beveled gears 5 and 6 teashaft? of the speed- 7 responsive device or, centrifuge centrlfuge C 1slntended tQ-HlOVQQ'COIltElCt disc 8 into engagement with-stationarycontacts 9 while the shaft l' is rotating, and to open these contacts assoon as" this shaft stops... "This centrifuge G may take various forms;

and in -its simplified construction shown coinprises a lower collar,fixed was shaft '7, an upper'collarslidable on said 'shaft'in'opposition to a spring, and springarms con-.

'necting said "collars and provided with weights. The shaft l'isconnected by a don ble iworm reduction gearing, comprising the worm'10,worm gear 11, shaft :12, worm 1'8, and 'worm' gear 14, to a circuitcontroller-shaft 15. "This reduction gearing is designed, in conformitywith the normal rnnningspeed of the motor 'M,'so as to cause the shaft15 to. make one complete revolution, during the time interval selectedfor acknowledgment, such as, for'examiple, fifteen or twenty seconds Theshaft 15' opens and closes three pairs of contacts at differentpositionsoftheshaft, and for different tions'of its revolution. Variousconstructions may be employed to perform this circuit'controllingfunction." In 'the form shown, a

' drum,- of suitable insulating material, is se- Ycuredto the shaft'15,and has fastened there- .Lon contact strips 1.61and 17 and a cam 18.

sliaft715 and its'drumare shown in the a 5 normal initial. position. TheContact strip 16 engages and bridges contact fingers 19, after the drumhas been moved a short dis tance from its initial positioncounter-clockwise, as indicated by the arrow, and maintains this contactuntil the drum has nearly completed one revolution. ,Gontact strip '17bridges the fingers QOlinTthe initial position of the drum, and for ashort distance of moveinent-thereof away from the lnitlal posit on.

The ca'm 18 engages a roller 21 in the initial position of the drum andZholds the spring finger or contact member 22 out of engagement with itscooperating contact for a small distance of movement of the drum fromits initial position." The sequence of opening and closing of thesecontacts will appear from the following explanation of the operation.

' 0pemtion.ll henthe train passes :a cant1on,or astop s1gnal,or acorresponding control point, at which it is ClBSlI'QCl' toenforceaclmowledgement, the contact A is opened,

breaking a normally closed stick circuit for the relay SR. As aconvenience in illustrationythis-circuit, and also theother circuitsshown, are indicated conveniently as terminating at B andG,indicatingoppositeterminals of the battery, turbo-generator, or othersuitable source of current. 1

The normally-closed. energizing circuit for r the relay SR may be tracedas f-ollows-:

commencingat1B, wire 25,0011tflClLAyWlI8 2.6,

frontcontact liof relay SR, wires27 and :28, relay SR, and wires-29 :and301 0 G.

Electroepneumatic valve EPV is normally energized by acircuit which mayhex-traced asfollows commencing at B, wires 81 and 32, contactmember .3of the reset switch RS and its normally closed contacts, wire 83,

.valve EPV, wire84c, frontcontact 2 of relay SR, and wires 35 and "30 to1G. Assuming first that the engineer does not properly acknowledge, whenthe contacts A open and break the normal energizing circuit for therelay SR, this relay is de-energized,

opening its front contact 2, and de -energizing contact member 3 ofswitch RS and its normally openeontactswires 37 and 28fre-lay SR, andwires 29 and 30 to C. -It will be evident tha-twhen this pick-up circuitis established,'the energizing circuit 'forthe valve EPV hereinbeforetraced, is at'the same time broken at'the normally closed contacts ofthe switch RS."Th-us, while the relay SR is reenergized, the :valveEPV-cannot be-energized, and the brakes released, lllllilllthB resetswitch BS is restored to its normal position.

Consequently, the reset switch cannot be carelessly-or: improperlyleftin the resetting position, but mnstlbe restoredto normalieach time, inorder to :permi't'the train-to proceed.

,Inor'der to prevent this automatic brake appl ca ion; and stopping ofthe train, -;the engn'icer 1S required to operate his acknowl ed ngcontactor AC: .prior to the opening of the contact-A andde-energi'zation.oftherer lay SR In other :words, the'engineer mustforestall the automatic brake application,

acting upon information obtained from the,

wayside" signals, or; suitable cab indicating means,'1fso provided. Whenthe engineer operates the acknowledging ,contactor 'AG,

closing its normally opencontacts',- the motor in isenergizedandstartedby'aci'rcuit as follows commencing at B, Wired0, switch' 23 down,"wirej4l,feontacts 1 7'.20, Wires l2 and '43, motofrM, and wire 44 to G;Shortly after the motor starts, andthe shaft has been turnedicounter-clockwise thron'gh Era small angle, the contacts 16 1'9-close,lighting an I indicator lamp 1 through a circuit from B,

1 wires and46, contacts 16 19, iwire' 47, "lampI andwirei48to(l-H'Be'fore these con- "tacts close, l1owever, the;cam.18 rides out 1from under the'roller'21, a1lowing the spring finger 22 to engage itscontact; and when the lamp I lights, the engineeris supposed toreturnthe acknowledging'contactor AG tothe normal pd'sition, establishingf'asecondenergizing circuit for the motor M as follows starting atB', wirelO, switch 23 np, fwire 49,

finger 22 down, wires andl l3, motor M,

andwire 44 to Cg; After ashortit'ime, sufi.

'cient to afford theengineernall reasonable latitude in restoring. hisacknowledging contact-or AG to norinal,i the' "coi1tact's 17-l-20 open,breaking the first energizingcircuit for the motorM although the circuitmay already have been broken at, 23- 11 by the engineer. If the engineerhas'properly returned'his acv knowledgingco'ntactor to I the normalposition, a supply of current to the motor is main- 7 tamed through thefinger'22, and the motor continues" to drive the shaft-15 until,'nearthe end ofjone revolution, the cam 18- 'engagesthe roller 2 1-an d openscontact at the finger 22.- The friction "of the parts-driven by themotor 'briri gsit quickly to rest ,and the parts'are so proportioned anddesigned that, once the finger 22 is ppenedfby thecam '18,the motor-cannot overr u to the point where this finger again'closed',bnt willstopand remain at rest until the acknowledging contactor isat ain o erted; r VVhileand'solong as the shaft is'bein rotated bYj he motor M,-thecentrifuge maintains the' contacts closed, establishing 'an'au-Xfliaryenergizing -'circuit forkth'e .re1ay- SR,Zincludinga shuntfor thecontact edging contactor in the operated position, with any effectbecause the shaft 15-will only *be rotated a short distanceuntil thecontacts 17-20 open, whereupon the motor stops, and

'the co'ntacts 8-9 open, eliminating the preventing or suppression ofautomz-itic'braking. vl-l'ence,if the engineer holds or fastens down hisacknowledging contactor, the brakes will be automatically applied at thenext steps "ping control point. If the motor shonld be- A, which maybetraced as follows from B, wires 45 and '57, contacts 8-9, wires 52citation of the" timing mechanism, constitutand 26, front contact 1 ofrelay SR, wires 27 vand'i28, relay SR, and wires 29 and 30 to C.

Thus, duringthe time interval or cycle or op- 7 inc; onerevolution :ofthe shaft'15, the relay SR is maintainedenergized, and theautoinaticbrake application prevented, in, spite ofthe Openingofthecontact A. I Obviously,v the engineer must operate his acknowledglngcontactor and get the shaft 4: in motion to close the contacts 8 and. 9before the contact A'opens'and the relay SR- is dc-energized; or, ln'other words, the engineer must forestall the automatic brakeapplication, If thecontact A'is operatedfquickly upon the reception acontrol influence from the-track'- way, without any precedlngintervening delay, the engineerniust observe the indica tions' of thewayside signals and operatehis acknowledging con-tactor AC beforepassing the control point'for the caution or stop signal; and if hefails to do'so, the relay SRis- 'de-energized, the brakes applied}, and'the train brought to a stop.

gPointing ont some of the "characteristic 7 features of the invention,iltshould be noted v that the engineer cannot hold his acknowlcolne'damaged, or its operating -circuits broken, or other failure occurpreventing the timing operation, the centrifuge C fails to rotateQandthe contacts 8 9 remain open, so that the brakes are applied at theffirst stop ping control point. If the timing mechanism 1 stops at anintermediate point in its cycle termine accurately when he shouldrestore hisacknowledging'contactor AG to. normal. In other words, whenthe lanipl lights, the

engineer knows "that the motor energizing circuit is closed atthecontactfin'ger 22,"ai1'd r v I that he should restore his'acknowledgingcontactor Ae'promptly, before th'e'motor circuit started, so

" broken at tl'ie contacts I'l These contact'sglY- QG are preferablymade to remain {preferably a made relativelyshort.

' I It will be obs 1 tinrehe -;.E1mit'e'd time control point; Inpractice,tli1s time interval rved that the engineer may "rate histn'owledging contactor any shes, and may hold it down as long as hepleases, without producing any automatic br'alre application; but if heholds it down,- the brakes are applied at the first 'stoppii-rg controlpoint, and if he operates the acknowledging. contactor too soon beforepassin-g the control point, the time element i-n'e'chanism completes itscycle and stops.

Consequently-the engineer in any event must form the a'cln i'owledgingact Within a efore passing each stopping isselect-ed to affordreasonable latitude ing the ratio of the reduction gearing between theshaft and shaft 15, or by varying the lspeed'of the motor M, by varyingits "oltagc, crby any other well known ex pedient, V Only onespecificembodiment of the presand. it should be understood that this isto illustrate the nature and purpose of the in vention, rather than itsscope and that various changes and modifications may be made in theconstruction and arrangement of ciras is shown and described, and inadapting the invention to various types of train control systems, allwithout departing from the invention or the idea of means underlying thesame. l

lVhat I claim is I 1 1. In an automatic'traln control system, thecombination with a brake applying appliance, a stick relay governingsaid appliance, means controlled from the trackway for temporarilyinterrupting the stick circontrolling. means for energizing the electricIfi tQT for elimited number of; revolutions for r of when closed, andmanually controllable time element mechanism for closing said contactsfor a limited timesai'd mechanism'comprlslng, an electric motor, acentrifuge for closing said contacts only while said motor is operating,an acknowledging contactor having normally closed and normally opencontacts,circuit controlling. means driven by the motor, an'energizing'circuit for the motor irrclu'dingi the normally. open contacts of theacknowledging contactor and normally closed contacts of said circuitcontrolling means, and an auxiliary energizing circuit for-said motorincluding the normally closed contacts of the acknowledging contactorand normally open cont-acts of said circuit controlling means, saidnormally open contacts of. the circuit controlling means being autoismati'cally closed after the motor has made a I few revolutions and beingmaintained closed until th'ejmotoi'has completed a number of revolutionsconsuming the desired time interval, said normally closed contacts ofthe circuit controlling means being automatically opened a shortinterval of time after said normally open contacts of the circuitcontrolling means have been closed;

ent nvention has been shown and described,

4-. acknowledging device of the character described comprising, apower-operated time element mechanism, manually operable means'shiftable to one position forinitiati'ng operation of'said mechanismbut ineffective in that positionto maintain such operation for morethana short interval of time, said manually operablemeans' when shifted toanotherjposition after such initiation of o'peratioir of said mechanismacting'to maintain that operation fora limited time, and brakepreventing means effective only while said mechanism is operating.

5. Ina train control system, acknowledging meanscomprising an electricpower-operated time element device having a cycle of operation consumingpredetermined time interval, manually controllable means effective ifactuated alternately during said cycle -of operation to two differentposit-iol'l's to cause said mechanism to com-plete'its cycleofoperation, and means efi'ectiv'e' only While said mechanismisfoperating to preventan autom-atic'b'rake application. V

An acknowledging device f-or train controlsystems for closing contactsfor a predetermined period of time only for each acknowledging actcomprising, a shaft, a

centrifuge driven by said shaft, contacts closed if said centrifuge" isrotated above a predeterminedspeed, a motor for rotating said shaft;afsta-rti-rr'g, circuit for starting said motor including; no ii-allyepenmanually' opthereof. 7 a 7. An acknowledging device for trainconerable contacts, and a stick circuit for said motor includingnormally open contacts closed during a predetermined extent ofrotationof said shaft, whereby said motor if once initiated will remain inoperation during a predetermined extent of rotation trol systems forclosing contacts for a predetermined period of time only for eachacknowledging act comprising, a shaft, a centrifuge driven b said shaft,contacts closed if said centri uge is rotated above a predeterminedspeed, a motor for rotating said shaft, a starting circuit for startingsaid gize d under favorable traific conditions ahead;an energizingcircuit for saidbrake control means including a front contact of saidcontrol relay; and means requiring recurrent manual action for keepingan auxiliary circuit for said brake control device motor includingnormally open manually op- I erablecontacts, and a stick circuit forsaid motor including normally open contacts closed'during apredetermined extent of rotationof said shaft and contacts closed onlyif said manually operable contacts are in their normal open condition,whereby said motor if once initiated will remain in operation for apredetermined cycle of operation provided said manually operablecontacts are returned to normal.

8. An acknowledging device for closing an auxiliary circuit for a brakecontrol device to maintain such brake control device energized while themain circuit for said brake control device is open comprising; a shaft;a motor for driving said shaft; a contact in such auxiliary circuitclosed only while said speed; two contacts closed alternately during Vthe operation of said motor, one-0f which is closed during apredetermined number of revolutions of said motor and the other of whichis closed at all'other times; a push button for controlling a normallyclosed contact and a normally open contact; and a circuit for said motorincluding two branch circuits in multiple onebranch of which includessaid one contact and said normally closed contact, and the other branchof which includes said other contact and said normally open contact.

9. Car-carried apparatus for train control systems comprising; normallyenergized brake control means; a control relay energized under favorabletraflic conditions ahead; an energizing circuit for said brake controlmeans including a frontcontact of said control'relay; and meansrequiring recurrent manual action for keeping an auxiliary circuit forsaid vbrake-control device closedincluding; a motor, a contact closedonly when said motor is rotating above a predetermined speed, andmanually operable means requiring intermittent operation to maintainsaid motor operating so long as said control relay is de-e'nergized'.

shaft is rotating above a predetermined 10. Gar-carried apparatus fortrain con trol systems comprising; normallyenergized brake controlmeans; a control relay ener-

